TERRAFORMING TERRA
We discuss and comment on the role agriculture will play in the containment of the CO2 problem and address protocols for terraforming the planet Earth.
A model farm template is imagined as the central methodology. A broad range of timely science news and other topics of interest are commented on.

Saturday, August 27, 2011

Neanderthal Genes Boosted Human Immunities

We are quickly getting a handle
on the mixing of Neanderthal genes and that of others.I suspect that before we are finished we will
find more than one species is locally common but naturally simplified as some
version of humanity or the other succeeded in simply through population
expansion.

Today the Americas have a
resident population approaching a billion individuals.The descendents of the original inhabitants including
all hybrids surely exceeds ten percent of the total depending where you wish to
draw the line.On going hybridization over
the next millennia will naturally disappear any local uniqueness, though
special features will remain in the genetic code and often appear.

These peoples constantly warred
on each other for women and this drove gene mixing at a fairly frantic
pace.The ability of our progenitors to
rapidly increase their populations spelled the end of the uniqueness of the Neanderthal
linage.

Human leucocyte antigen (mauve) is expressed on the outside of white
blood cells

Sexual relations between ancient humans and their evolutionary cousins
are critical for our modern immune systems,researchers
report in Science journal.

Mating with Neanderthals and another ancient group called Denisovans
introduced genes that help us cope with viruses to this day, they conclude.

Previous research had indicated that prehistoric interbreeding led to
up to 4% of the modern human genome.

The new work identifies stretches of DNA derived from our distant
relatives.

In the human immune system, the HLA (human leucocyte antigen) family of
genes plays an important role in defending against foreign invaders such as
viruses.

The authors say that the origins of some HLA class 1 genes are proof
that our ancient relatives interbred with Neanderthals and Denisovans for a
period.

“Start Quote

Getting these genes by mating would have given an advantage to
populations that acquired them”

Peter Parham

At least one variety of HLA gene occurs frequently in present day
populations from West Asia, but is rare in
Africans.

The researchers say that is because after ancient humans left Africa
some 65,000 years ago, they started breeding with their more primitive
relations in Europe, while those who stayed in Africa
did not.

I have real
problems with the assumption that Neanderthals were more primitive.A different lifeway adapted to the conditions
but no more primitive in that sense than the Masai.Besides, their brain capacity was larger than
ours and that is usually a good hint.

"The HLA genes that the Neanderthals and Denisovans had, had been
adapted to life in Europe and Asia for several hundred thousand years, whereas
the recent migrants from Africa wouldn't have had these genes," said study
leader Peter Parham from Stanford University School of Medicine in California.

"So getting these genes by mating would have given an advantage to
populations that acquired them."

When the team looked at a variant of HLA called HLA-B*73 found in
modern humans, they found evidence that it came from cross-breeding with
Denisovans.

Scanty remains

While Neanderthal remains have been found in many sites across Europe
and Asia, Denisovans are known from only a finger and a tooth unearthed at a
single site in Russia,
though genetic evidence suggests they ranged further afield.

"Our analysis is all done from one individual, and what's
remarkable is how informative that has been and how our data looking at these
selected genes is very consistent and complimentary with the whole genome-wide
analysis that was previously published," said Professor Parham.

A similar scenario was found with HLA gene types in the Neanderthal
genome.

"We are finding frequencies in Asia and Europe
that are far greater than the whole genome estimates of archaic DNA in modern
humans, which is 1-6%," said Professor Parham.

The scientists estimate that Europeans owe more than half their
variants of one class of HLA gene to interbreeding with Neanderthals and Denisovans.

Asians owe up to 80%, and Papua New Guineans up to 95%.

Uneven exchange

Other scientists, while agreeing that humans and other ancients
interbred, are less certain about the evidence of impacts on our immune system.

"I'm cautious about the conclusions because the HLA system is so
variable in living people," commented John Hawks, assistant professor of
anthropology at the University
of Wisconsin-Madison, US.

DNA from a tooth (pictured) and a finger bone show the Denisovans were
a distinct group

"It is difficult to align ancient genes in this part of the
genome.

"Also, we don't know what the value of these genes really was,
although we can hypothesise that they are related to the disease environment in
some way."

While the genes we received might be helping us stay a step ahead of
viruses to this day, the Neanderthals did not do so well out of their encounters
with modern human ancestors, disappearing completely some 30,000 years ago.

Peter Parham suggested a parallel could be drawn between the events of
this period and the European conquest of the Americas.

"Initially you have small bands of Europeans exploring, having a
difficult time and making friends with the natives; but as they establish
themselves, they become less friendly and more likely to take over their
resources and eliminate them.

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About Me

Apr 2017 - 4.1 Mil Pg Views, March 2013 - Posted my paper introducing CLOUD COSMOLOGY & NEUTRAL NEUTRINO rigorously described as the SPACE TIME PENDULUM, September 2010 I am pleased to report that my essay titled A NEW METRIC WITH APPLICATIONS TO PHYSICS AND SOLVING CERTAIN HIGHER ORDERED DIFFERENTIAL EQUATIONS' has been published in Physics Essays(AIP) and appeared in their June 2010 quarterly. 40 years ago I took an honors degree in applied mathematics from the University of Waterloo. My interest was Relativity and my last year there saw me complete a 900 level course under Hanno Rund on his work in relativity,as well as differential geometry(pure math) and of course analysis. I continued researching new ideas and knowledge since that time and I have prepared a book for publication titled Paradigms Shift&. I maintain my blog as a day book and research tool to retain data and record impressions and interpretations on material read. Do join my blog and receive Four items of interest daily Monday through Saturday.